Process of preparing cobalt hydrocarbonyls



United States Patent Int. Cl. C07f 15/06; C07c /14;B01j11/22 US. Cl.260-439 3 Claims ABSTRACT OF THE DISCLOSURE The compounds are of theclass of cobalt carbonyls, HCo(CO) (PR wherein R is alkyl from 1 to 10,useful as hydrogenation catalysts.

Our invention relates to cobalt hydrocarbonyls, method of theirpreparation and their use as hydrogenation catalysts.

The compounds which are the object of the present invention, have theformula:

wherein R is an alkyl containing from 1 to carbon atoms.

The literature shows the use of several cobalt-carbonyls, containingphosphines, as catalysts. For example, French Patent 1,345,933 describesa hydroformylation process of olefins whereincobalt-trioarbonyl-tributylphosphine having the formula [Co(CO) (PBu isused as the catalyst. The preparation and the use of this compound arealso described in the Dutch patent application No. 6,400,701.

We have found that cobalt hydrocarbonyls of the general Formula -I,which we have prepared, are active hydrogenation catalysts. These newcompounds can be used in hydrocarbon (aliphatic, cycloaliphatic,aromatic) solution or in the solution of the substances themselves to bereduced. The catalysts easily hydrogenate, in homogeneous phase, thesaturated and unsaturated aldehydes, ketones, alkenes, alkynes, etc.

The compounds of the present invention can be obtained by one of thefollowing methods:

(21) Reaction in hydrocarbon solution at 50200 C. under hydrogenpressure (20-30 atm.) of a cobalt carbonyl having the formula [Co(CO)(PR with a trialkyl-phosphine, in the presence of an aliphaticalphaolefin. The alpha-olefin favors the extraction of a carbonyl groupfrom the starting complex.

(b) Simple heating at 140-180 C., under hydrogen pressure, of ahydrocarbon solution of [Co(CO) (PR 1 and trialkyl-phosphine in anamount suflicient so that the substitution of a CO group for each cobaltatom takes place.

(c) Direct synthesis from a Co++ soluble salt with an organic acid (egcobalt 2-ethylhexanoate), trialkylphosphine and carbon oxide in molarratio in hydrocarbon solution at 100180 C. under hydrogen pressure.

The solutions obtained according to any of the abovementioned methodsare clear and vary in color between yellow-brown and red-brown. The IR.spectra, determined by Perkin-Elmer spectrometer, type 21, using a NaClcell of 0.05 mm., show bands at 5.05-5.08, 5.11- 5.14 and 5.26-5.29microns.

The following examples are not intended to limit the ice invention,describe the methods of preparation of the catalyst and someapplications as a catalyst for the hydrogenation of organic compounds.

EXAMPLE 1 A 200 c.c shaking stainless steel autoclave provided Withmanometer, is carefully swept by pure nitrogen. 2.31 g. ofdicobalt-octacarbonyl (6.75 mM.) dissolved in 100 cc. of n-heptane and3.6 g. of freshly rectified triethylphosphine (30.5 mM.) are thenintroduced. The autoclave and contents (whole) are agitated at roomtemperature for 30 minutes during which time the following reactiontakes place:

At the end of reaction, the gases are discharged in order to remove thecarbon oxide produced. The whole is then heated under agitation at C.for 30 minutes, in order to transform the salt into the covalentcompound [Co(CO) (PEt Then 25 atm. of hydrogen are introduced and thewhole is heated at 155 C. for 60 minutes, at the end thereof the wholeis cooled and the gases are discharged. This heating operation underhydrogen pressure is repeated nine times, thus obtaining a clearsolution of an orange shade, which at the LR. spectrum, shows bands at5.07, 5.11 and 5.26 microns characteristic of the HCo(CO) (PR compounds.

EXAMPLE 2 This example is carried out in the same manner and with thesame amounts of reagents described in the preceding example usingtri-n-hexyl-phosphine instead of triethyl-phosphine. At the end of thereaction, a clear solution of red-brown color, which at I.R., showsbands at 5.06, 5.13 and 5.28 microns, characteristic of the compounds,is obtained.

EXAMPLE 3 11.6 mM. of H-Co(CO) (PEt contained in 130 cc. of heptanesolution, are introduced in the 200 cc. autoclave together with 7.9 g.(136 mM.) of pure acetone. atm. of hydrogen are compressed at roomtemperature and the whole is heated at 155 C. The adsorption of hydrogenbegins at 145 C. The reaction is continued for 6 hours and 20 minutes at155 C. and atm. Upon completion, a clear orange solution, which at thegas chromatography, is seen to contain mM. of isopropyl alcohol and 19.5mM. of acetone, is obtained.

EXAMPLE 4 Into the 200 cc. shaking autoclave, carefully washed withnitrogen, cc. of a heptane solution containing 11.8 mM. of H-Co(CO) (PEtand 8.12 g. (140 mM.) of pure acetone are introduced. 90 atm. ofhydrogen are compressed at room temperature and the autoclave andcontents are heated at C. The hydrogen adsorption begins at 147 C. andthe reaction is carried out at 110 atm. and at 160 C. After 9 hours and50 minutes the adsorption ends. A clear red-brown solution, which bygas-chromatography analysis, is seen to contain 110 mM. of isopropylalcohol and 26 mM. of acetone, is discharged.

3 EXAMPLE Into the 200 cc. stainless steel shaking autoclave providedwith manometer and carefully Washed with pure nitrogen, a homogeneoussolution consisting of [Co(CO) PBu (6.67 mM.) g 4.60 n-Heptane cc 95Octene-l (126 mM.) g 14.1 P(n-C H (16.8 mM.) g 3.39

is sucked in. 25 atm. of hydrogen are then introduced and the autoclaveand contents are heated at 119 C. maintaining the pressure during theadsorption between 35 and 30 atm. Within /2 hours a total decrease of53.5 atm. takes place. The clear brown solution obtained shows LR. bandsat 5.06, 5.13 and 5.28 microns.

When the reaction is carried out as described above, but in the absenceof free phosphine, a clear red solution, which at the LR. shows a singlestrong band at 5.13 with a shoulder at 5.07, characteristic of thestarting catalyst [Co(CO) PBu is obtained.

EXAMPLE 6 Working as in Example 5, the following are introduced into theautoclave:

[Co(CO) PBu (6.77 mM.) g 4.67 n-Heptane cc 95 P(I1-C4H9)3 111M.) g

25 atm. of hydrogen are then introduced. The whole is heated up to 160C. and maintained at this temperature for one hour. The autoclave isthen cooled and the gases vented. This operation is repeated for tenadditional repetitions. Thus a clear brown solution is obtained. Thissolution shows LR. bands at 5.06, 5.13 and 5.28 microns as the solutionobtained according to Example 5.

By concentration of the solutions obtained in the Examples 5 and 6 toremove all traces of volatile substances, an oily, brown-red liquid isobtained which gives the following analysis.

Found: Co=10.9%, C=60.26%, H=10.6%, Co: 10.35%. Theoretical forCo:2CO:2PBu Co=11.37%, C=60.20%, H=10.41%, CO=10.79%.

The I.R. spectrum of the oily compound (thickness less than 0.01 mm.)shows bands at 5.08, 5.14 and 5.27 microns, corresponding to those ofthe compound in solution prepared according to the above-describedmethods.

The NMR spectrum carried out in an apparatus at 60 me. shows a triplet(J =45 c./s.) at 11.25 ppm. at higher fields from Si(CH which positionis characteristic for the hydrides.

By heating of the oily compound (11.5 mM.) in heptane solution (62 g.)under atm. of CO, for 4 hours at 160 C., the yellow-brown solution turns"blood-red. In the gases produced, the hydrogen (5 mM. H developed,corresponding to 87% of the hydrogen of the hydride, is found.

The LR. spectrum of the solution shows strong bands ofcobalt-tricarbonyl-phosphine and only very weak bands ofcobalt-dicarbonyl-hydride.

This confirms the structure:

' )zl 4 9)3lz for the compound under examination.

EXAMPLE 7 In the 200 cc. autoclave a solution containing:

Cobalt (II) 2-ethylhexanoate (13.5 mM.) g 4.66 n-Heptane cc 95 P(n-C. H(27 mM.) g 5.45

is introduced.

After heating at 160 C., 605 N cm. (27 mM.) of carbon monoxide and 40atmospheres of pure hydrogen are introduced. Rapid adsorption, whichpractically goes to completion within 15 minutes takes place. The clear4 brown solution thus obtained shows LR. bands at 5.06, 5.13 and 5.28microns.

EXAMPLE 8 In the 200 cc. autoclave an amount of the solution of thecobalt complex, obtained according to Example 2, containing 10.96milliatoms of cobalt, is introduced.

Then 9.9 g. (137.5 mM.) of freshly distilled n-butyraldehyde and 25atmospheres of hydrogen are added. The autoclave and contents are heatedat 160 C. carrying out the reaction between 35 and 30 atmospheres ofpressure. The adsorption begins at 135 C. and ends practically within 40minutes, while the temperature raises progressively up to 160 C. Thereaction solution, clear and brown-colored, contains 122.5 mM, ofn-butyl alcohol, 1.4 mM. of n-butyraldehyde and 11 mM. of 2-ethylhexylalcohol.

EXAMPLE 9 11.6 mM. of HCo(CO) (PBu contained in 100 cc. of heptanesolution, are introduced in the 200 cc. autoclave together with 7.78 g.(134 mM.) of freshly distilled pure acetone.

atmospheres of hydrogen are introduced and the whole is heated at 160C., carrying out the reaction between 110 and 100 atmospheres. Thesolution discharged is clear and shows the same color of the startingsolution. Gas chromatography shows the solution to contain 132 mM. ofisopropyl alcohol and 1.2 mM. of acetone.

When the reaction is carried out under the same conditions, but at lowerH pressure (35-30 atmospheres), a reaction product containing 123 mM. ofisopropyl alcohol and 11 mM. of acetone is obtained.

EXAMPLE 10 In the 200 cc. autoclave, 100 cc. of a heptane solution,prepared according to Example 3, containing 11.3 milliatoms of cobaltand 2.9 g. (26.4 mM.) of actyne-l are introduced. 21 atmospheres ofhydrogen are introduced and the whole is heated at 75 C. At thistemperature the adsorption begins, which is completed within 15 minutes.The clear brown solution obtained from the reaction contains 19.8 mM. ofoctene-l and 5.28 mM. of octane.

When the reaction is carried out under the same conditions, but at 160C., the octyne is quantitatively reduced to octane.

EXAMPLE 1 1 In the 200 cc. autoclave, 100 cc. of a heptane solution ofthe catalyst prepared according to Example 1, containing 11.7 milliatomsof cobalt, are introduced. After having introduced 10.2 g. (243 mM.) ofpropylene, the whole (autoclave and contents) is heated up to 120 C. and35 atmospheres of hydrogen are introduced. A quick adsorption of thehydrogen occurs immediately and ends within 23 minutes. Upon completionof the reaction, the gases recovered and the solution show 233 mM. ofpropane by gas-chromatography.

EXAMPLE 12 In the 200 cc. autoclave, 100 cc. of heptane solution of thecatalyst prepared according to Example 1, containing 11.7 milliatoms ofcobalt are introduced. After introduction of 16.6 g. (132 mM.) offreshly distilled Z-ethyl-hexenal, 75 atmospheres of hydrogen arecompressed and the whole is heated up to 104 C. At this temperature, thehydrogen adsorption begins and ends within minutes, while the pressureis kept between 90 and atmospheres. The extracted solution is clear,brown-violet colored, and shows the same I.R. band as the startingcatalytic solution, while containing 132 mM. of ethyl-hexyl alcohol.

5 We claim: 1. The process for preparing cobalt hydrocarbonyls of theformula wherein R is an alkyl containing from 1 to 10 C which comprisesreacting a cobalt-carbonyl having the formula [Co(CO) PR in hydrocarbonsolution at 140180 C. under hydrogen pressure, with an excess oftrialkylphosphine PR wherein R is an alkyl having from 1 to 10 C.

2. The process for preparing cobalt hydrocarbonyls of the formulawherein R is an alkyl containing from 1 to 10 C which comprises reactinga soluble salt of C0++ and an organic acid in hydrocarbon solution at100-180 C., under hydrogen pressure, with a trialkylphosphine PR whereinR is an alkyl having from 1 to 10 C and carbon monoxide, with a molarratio C0:CO:PR substantially equal to 1:212.

3. The process for preparing cobalt hydrocarbonyls of the formulaReferences Cited Heber et al.: Chem. Ber, 98 (1965) pp. 2933-6 and 2938.

Booth: Advances in Inorganic Chemistry and Radiochemistry, vol. 6(1964), Academic Press, New York, N.Y., p. 22.

TOBIAS E. LEVOW, Primary Examiner A. P. DEMERS, Assistant Examiner US.Cl. X.R.

